Cutting carbon is appallingly complex as well as costlyALTHOUGH Britain’s energy companies are no longer nationalised industries, they are still, to some extent, arms of the Treasury. When the government decides on a way to make Britain greener—such as joining the European emissions-trading scheme, which puts a price on carbon, or the renewables obligation, which subsidises wind, biomass and solar power, or levies to pay for carbon sequestration and storage or renewable heating—utilities pay for it and pass the costs on to their customers. As such policies grow in ambition, so does the bill to consumers.On July 27th, as part of its new “annual energy statement”, the Department of Energy and Climate Change put some numbers to this effect. Green policies will raise domestic gas prices in 2020 by 18% and electricity prices by 33%, it said. For nondomestic users the impact will be greater—24% and 43% respectively—and other estimates put the figures higher still. ......